The present invention relates to web splicers and, more particularly, to a web splicing system that features an easily threadable and loadable web apparatus that provides safety, convenience, and improved ergonomics.
Through the years, a great number of designs for web splicing machines have been proposed. Many of these designs are very complex and their reliability is poor. Machines of complexity and poor reliability are usually those featuring movable turrets and precision load and splice timing. Controllers and/or computers are usually required to provide this precise timing. These complex machines tend to be more costly and difficult to load and thread. The threading and loading difficulties also give rise to lower operating safety and poor ergonomics.
The web splicing machine of this invention is a simple apparatus that is easy to load and thread, is safer, less costly, and does not require a controller or a computer to provide splice timing. Moreover, the splicing operation is performed on the fly and minimizes tension along the web material.
The web splicer of the invention is mounted on a movable assembly that is withdrawn from the moving web to provide the operator with a facile means for threading the new web roll into the apparatus. In the past, operators would have to extend their limbs into the moving machinery, thus giving rise to a greater possibility for injury. U.S. Pat. No. 3,841,944, issued to W. W. HARRIS, JR. for WEB SPLICING APPARATUS, discloses a machine adapted to splice a web from a reserve roll to the web from an expiring supply roll. Two carriages rotate through an arc as they move toward and away from each other. Within each carriage, flat plates or holding surfaces are disposed in parallel planes. In operation, one of the plates is extended towards the other by a motor and piston rod. The web is disposed above the plate, so a tension spike is produced as the plates engage each other. In effect, the web and its splice are pulled through a vise formed by the two plates. Such a system is completely inadequate for use with thin film material, which is prone to rupture when subjected to tension.
Another drawback of the HARRIS system is the cutter, used to cut the tail of the expiring roll after the splice. Since the HARRIS apparatus is used in a commercial paper mill environment, safety is not an issue, so the cutter is exposed. Moreover, its application to the web results in a deflection thereof, prior to bursting the web material. Once again, this severing operation introduces unwanted tension along the web, which is especially unacceptable when handling thin film.
U.S. Pat. No. 4,722,489, issued to THOMAS WOMMER for DEVICE FOR FEEDING MATERIAL TAPES, also discloses a splicing apparatus. Once again, however, flat fixing bars or plates are used to push the web material from supply and expiring rolls towards each other. In WOMMER, however, the splicing operation is accomplished while the two segments of web material to be spliced are stationary with respect to each other. A magazine or accumulator is used to allow the web to continue to be extracted from the supply roll without affecting the tension of the web while the material is pressed between plates and the movement thereof is halted. The large moments of inertia of commercial web rolls makes instantaneous starting and stopping of their motion impossible, so that the WOMMER accumulator is necessary for his separate, discrete splicing step.
The movable splicing assembly of the current invention eliminates operator contact with the moving web. In addition, the movable assembly brings the threading apparatus to the operator, thus improving ergonomics.
In accordance with the present invention, there is provided a movable web splicing system for splicing a new web roll to an expiring web roll. The movable system comprises a first work station and a second work station. Each work station comprises respective first and second, movable threading assemblies. Each of the threading assemblies is movable between a web splicing/feeding position, where they are adjacent each other, and a web threading position at an extended location to each other.
Each assembly has a first and second juxtaposed threading roll and a vacuum roll, having a series of air holes disposed therein, for drawing a vacuum upon the edge of a threaded web. The vacuum roll is disposed adjacent the two juxtaposed threading rolls. The vacuum roll of the first movable threading assembly is movable between a splicing position and a non-splicing position. A crank arm connected to, and powered by, a pneumatic piston pivotally supports this vacuum roll, so that it is caused to move between its splicing and non-splicing positions. Another pneumatic piston is connected to a web clamp disposed adjacent the first positioned threading roll of each of the first and second movable assemblies. The pneumatically controlled clamps of each assembly are movable between a web clamping position adjacent each first juxtaposed threading roll, and a non-clamping position at a non-extended position with respect to said respective, first, juxtaposed threading roll. The vacuum roll of the second movable assembly is positioned in place. The pneumatic piston of this assembly operates and connects only to the web clamp disposed adjacent the first juxtaposed threading roll. A pneumatically controlled cutting knife is disposed between the vacuum roll and the second juxtaposed threading roll of each assembly, extremely close to the web itself. Moreover, an anvil having a groove or slot allows severing of the web cleanly and quickly, without deflecting the web prior to bursting.
The splicing machine operates so that a second web supply roll that is about to become exhausted is threaded upon the second assembly that is disposed at its splicing position. The second, or old, web is movably threaded around the juxtaposed threading rolls and the vacuum roll whose vacuum is inoperative in free flow. The web is freely flowable about all three rolls. The pneumatic piston controlling the clamp for the first positioned roll is nominally in its non-extended position. As the second web is about to become exhausted, the operator of the splicing system mounts a new web supply roll upon a mandrel located at the first work station. After the new supply roll is rotatively secured upon the mandrel, the operator withdraws the first assembly from its web splicing/feeding position to its web threading position located adjacent the operator. The operator then proceeds to thread the new supply web about the three rolls. The leading edge of the web is positioned about the vacuum roll. The vacuum roll is actuated to draw its vacuum through perforations in the surface of the roll and the leading edge of the new web is pressure adhered thereto.
The pneumatic piston is actuated to move the web clamp into adjacent contact with the first positioned roll, so that the interdisposed new web is held firmly to the first positioned roll. This prevents the new web from tending to slip backwardly and withdraw into the new supply roll. The new web being firmly threaded within the first assembly, the operator pushes a button that moves the first assembly into its splicing and feeding position.
When the first assembly moves into the splicing and feeding position, the pneumatic piston of the first assembly actuates, causing the crank arm to move the first vacuum roll and its respective web into contact with the old web disposed on the second vacuum roll. At the same time, the first clamp is moved to its non-extended position, thus releasing the new web for movement about the first juxtaposed threading roll.
The leading edge of the new web has an adhesive surface that adheres to the old, second web, when the two vacuum rolls come into contact. In this way, the new, first web is spliced to the old, second web. Simultaneously therewith, the second cutting blade is pneumatically actuated, thus severing the old, second web from its respective supply roll. This completes the splicing operation.
When the new, first web becomes exhausted, a new, second web supply roll is mounted upon the second work station, and the second movable assembly is withdrawn from the splicing/feeding position. After threading the new, second web into the second assembly, in similar manner to that previously described for the first assembly, the operator pushes a button at the second station to actuate the splice sequence. The crank arm of the first assembly causes the first vacuum roll to contact the second vacuum roll, thus causing contact of the old, first web, with the new, second web. The second clamp is caused to move to its non-extended position, thus freeing the second, new web for movement with respect to the first juxtaposed threading roll of the second assembly. The vacuum is then released on the second vacuum roll. The first cutting knife then cuts the first, old web, thus completing the splice, as before. An accumulator device, or xe2x80x9cdancerxe2x80x9d, is located downstream from the first and second work stations along a web feed path, in order to maintain the proper tension in the moving web during the splice. The splicing system of this invention is configured to allow for the splice when the web is either stationary or moving. The timing of each component during the splicing sequence can be accomplished by simple electronic relay or delay mechanisms.
It is one object of the invention to provide an improved web splicing system for use on the fly.
It is an object of this invention to provide a movable splicing assembly for a web splicing system, wherein the system is easier than conventional apparatus to thread and is safer to operate.
It is another object of the invention to provide an ergonomic web splicing assembly wherein the operator can move the splicing assembly to provide easy access for threading the web thereupon.
It is a further object of this invention to provide a less complicated web splicing system that is more reliable than conventional apparatus and less costly to construct.
It is yet another object of the invention to provide a cutting mechanism that is both safe and non-disruptive to the flow of the web material.
It is still a further object of the invention to provide a splicing device for web material that can be operated on the fly with thin film, since the web is not appreciably deflected from its path during the splice.